1. Field of the Invention
The present invention relates to an apparatus, a method, and a computer program product for processing image, and more particularly, to an apparatus, a method, and a computer program product for embedding predetermined information in an image.
2. Description of the Related Art
Developments are in progress in technologies for embedding information in an image with, for example, a barcode technology, a digital watermark technology, or steganography for, for example, tracing, protecting copyrights, detecting falsification, or adding meta information. Such technologies are mainly divided into a fragile type and a resistance-type, and the two types are used for different purposes. With respect to the resistance type, a copy image acquired by copying an original image embedded with information (i.e., original image containing embedded information) can contain the embedded information.
A copy image (electronic image) acquired by electronically copying an original image containing embedded information can contain the embedded information. On the other hand, a print image acquired by printing the electronic image on a paper recording medium loses embedded information in many cases, because image degradation tends to occur on a paper recording medium. To prevent this problem, technologies for embedding information resistant to copying and printing are disclosed in Japanese Patent Application Laid-open No. 2003-209676, Japanese Patent Application Laid-open No. 2005-102264, Japanese Patent Application Laid-open No. 2005-182442, and Japanese Patent Application Laid-open No. 2006-050551.
However, even if the technologies for embedding information resistant to printing and copying are employed, image degradation tends to occur in a copy image acquired by copying an image containing embedded information and copied on a paper recording medium. This increases the possibility of loosing the embedded information.
Because image degradation tends to occur with the technology for embedding information having high resistance generally, a technology for embedding information having low resistance is useful to keep its image quality in printing an image.
To solve the above problem, a method of newly embedding information in an original image previously containing embedding information has been developed.
With this method, however, a time consuming process is required for extracting the information embedded in the original image before newly embedding information.